Hood lifting mechanisms include linear actuators that push the hood upward in the event of a collision with a pedestrian or imminent impact with a pedestrian. This upward movement creates space between the hood and the vehicle body and allows the hood to absorb the impact of the pedestrian, preventing the pedestrian's head or body from striking parts of the vehicle that are below the hood (e.g., the engine block).
The linear actuator includes a piston within a housing and a combustion chamber in fluid communication with the piston. Double backed adhesive tape is wrapped around at least one end of the piston to hold the piston in place within the housing to prevent the piston from rattling. The adhesive tape also holds the piston in place during expansion due to temperature changes in the combustion chamber. This expansion causes the piston to push on the environmental cap over time, creating a gap that exposes the actuator to environmental elements. However, the adhesive tape solution is expensive from a component standpoint and cumbersome for manufacturing.
Therefore, there is a need in the art for an improved linear actuator.